Optoma - 21.50 mm to 28.70 mmf/3 - Standard Throw Zoom LensOptomas 21. 50 mm to 28. 70 mm f 3 Standard Throw Zoom Lens is a precision projection accessory built for versatility, creativity, and reliable performance. This 1. 3x optical zoom lens expands your projection toolkit, letting you adapt quickly to a wide range of room sizes and throw distances without swapping lenses. Whether youre teaching in a classroom, delivering a high stakes business presentation, or enjoying immersive home entertainment, this